I think the problem is that the 'chds' parameter is new (that is, not in the original Google Chart API) and Eastwood doesn't implement it yet. I need to review what has been added in the latest release of the Google Chart API and see how easily it can be implemented. There will be a new Eastwood release in May, if things go to plan.

Originally the text encoding required you to enter values between 0.0 and 100.0 (the axis, irrespective of the labels you attach to it, behaves as if it is showing values in the range 0.0 to 100.0). So here is your chart recoded in the old-style:

Now, it looks as though you can use any range of values, but now you have to provide (using the new 'chds' parameter) the min and max values so it knows what the axis range is. That will be simple to implement in Eastwood, so I'll get that fixed for the next release.